Compactable RF membrane antenna

ABSTRACT

Exemplary embodiments are described herein for compactable antennas. Exemplary compactable antennas include a support structure and a reflector surface. The support structure may directly or indirectly define the reflector shape. Exemplary embodiments comprise deployable support structures to permit the compactable antenna to have a smaller volume stowed configuration and a larger volume deployed configuration.

PRIORITY

This application is a U.S. national stage application under 35 USC § 371of International Application No. PCT/US17/20056, filed Feb. 28, 2017,claiming priority to U.S. Application No. 62/301,486, filed Feb. 29,2016, each of which is incorporated by reference in its entirety intothis application.

BACKGROUND

Large dish antennas have played a substantial role in astronomy,collecting radio-frequency (RF) waves from nearby planets and stars, aswell as intergalactic waves from the far reaches of the universe. Theircontribution has consisted of data that explain mysteries of the birthof the universe from the earliest moments of the big bang. Morerecently, they are aiding in the discovery and characterization ofexoplanets orbiting stars in our own galaxy.

Concurrently, advances in miniaturizing technology have allowedspacecraft to shrink in size and weight while maintaining capabilitiesrivaling that of much larger traditional satellites and crafts. However,the sensitivity and resolution of radar antenna detection dependsdirectly on the area of the antenna receiver or dish. So, while otherspacecraft components such as high-speed processors, high energy densitybatteries, solar cells, inertial measurement units, divert and attitudecontrol systems, etc. have shrunk in size and weight in today'ssmallsats and nanosats, the antenna area must remain large to providethe required performance.

This demand for large area has resulted in new concept designs for RFantennas that maintain large area while allowing for highly compactablestorage during launch into space. The antenna must be able to be foldedinto a small volume in a rocket payload, and, once in space, deploy toits full extent while maintaining an accurate parabolic reflectivesurface quality and shape that permits the collection of undistortedradio wave information from light years away.

Conventional stowable antennas include pre-formed rigid structures thatinclude discrete positions that permit the segments to fold into acollapsed configuration. By extending the structure by unfolding andlocking these joints, the structures defines a desired deployedconfiguration. For example, rigid sheets may include hinges betweensheets to permit the antenna to unfold from a stowed configuration to adeployed configuration. Similarly, a support frame of an antennastructure may include rigid segmented rods that form foldable links. Thesupport frame may be folded at discrete positions in the stowedconfiguration and unfolded and locked in a deployed configuration.

Conventional stowable antennas that do not include static, pre-formedshapes may include inflatable structures. These structures areessentially balloons in the shape of the desired final form. Thesesystems, however, require additional components for storing and applyingthe inflation gas or substance to deploy the structure. Therefore, thesestructures may provide a benefit in not requiring a specific or staticstored configuration mandated by preformed and static structures.However, these structure require additional space and weight bededicated to deployment of the structure.

SUMMARY

Exemplary embodiments are described herein for compactable antennas.Exemplary compactable antennas include a support structure and areflector surface. The support structure may directly or indirectlydefine the reflector shape. Exemplary embodiments comprise deployablesupport structures to permit the compactable antenna to have a smallervolume stowed configuration and a larger volume deployed configuration.

DRAWINGS

The drawings and following associated descriptions are provided toillustrate embodiments of the present disclosure and do not limit thescope of the claims. Corresponding numerals indicate correspondingparts.

FIG. 1, FIG. 2, and FIGS. 3A-3B illustrate exemplary symmetric antennaconfigurations.

FIG. 4 illustrates an exemplary asymmetric reflector.

FIG. 5 illustrates an exemplary support structure for a reflector.

FIG. 6A illustrates an exemplary deployable antenna configuration. FIGS.6B-6D illustrate exploded component parts from FIG. 6A.

FIG. 7 illustrates an exemplary deployable antenna in a deployedconfiguration.

FIGS. 8A-8B illustrate an exemplary stowage component view of FIG. 6A.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Embodiments of systems, components and methods of assembly andmanufacture will now be described with reference to the accompanyingfigures, wherein like numerals refer to like or similar elementsthroughout. Although several embodiments, examples and illustrations aredisclosed below, it will be understood by those of ordinary skill in theart that the inventions described herein extends beyond the specificallydisclosed embodiments, examples and illustrations, and can include otheruses of the inventions and obvious modifications and equivalentsthereof. The terminology used in the description presented herein is notintended to be interpreted in any limited or restrictive manner simplybecause it is being used in conjunction with a detailed description ofcertain specific embodiments. In addition, embodiments of the inventionscan comprise several novel features and no single feature is solelyresponsible for its desirable attributes or is essential to practicingthe inventions herein described.

Although certain aspects, advantages, and features are described herein,it is not necessary that any particular embodiment include or achieveany or all of those aspects, advantages, and features. Some embodimentsmay not achieve the advantages described herein, but may achieve otheradvantages instead. Any structure, feature, or step in any embodimentcan be used in place of, or in addition to, any structure, feature, orstep in any other embodiment, or omitted. This disclosure contemplatesall combinations of features from the various disclosed embodiments. Nofeature, structure, or step is essential or indispensable. Features mayalso be integrated or subdivided as necessary, such that the anycombination of features, whether integrated, separated, removed, added,duplicated, or otherwise recombined fall within the scope of the instantdisclosure.

Exemplary embodiments described may incorporate a shape memory compositedefining a support framework, defining a support structure, orintegrated into all or a portion of a non-structured collapsibleantenna. Although embodiments described herein are in terms of a shapememory composite, exemplary antenna configurations may be novel bythemselves. Therefore, the described structure may be made using anyconventional deployable antenna material. Exemplary embodiments includetwo inventive designs for compactable RF antennas comprised of membranereflectors. These designs are exemplary only and features may berecombined between them as necessary to achieve a given function.Although described in terms of radio frequency (RF) reflectors,exemplary embodiments may be used in other applications, such asreflectors for light or for transmitting/receiving other signals.Exemplary embodiments of the deployable structure may be used in otherapplications as well.

FIG. 1 illustrates an exemplary compactable membrane antenna. Theantenna 10 includes a reflector 20 configured to receive an RF signal(dashed line) and direct the signal or wave to a collector 12. The shapeof the reflector 20 is important to position the reflective surface in aproper location relative to the collector such that the received signalcan be properly positioned at the collector. As shown in FIG. 1, asingle reflector is used with a collector. However, any combination ofreflectors may be used. For example, FIG. 2 illustrates a similarreflector, but the collector is an extended configuration in which aportion of the collector is positioned behind the reflector and areceiving portion is positioned in front of the reflector. Other dualreflector configurations, such as that illustrated in FIGS. 3A-3B mayalso be used. In this case, a primary reflector is similar to that ofFIG. 1, and a secondary reflector is positioned at the receivinglocation of the primary reflector. The secondary reflector is thenconfigured to direct the received RF signals from the primary reflectorto the collector. The collector may be positioned behind the primaryreflector with a passage or hole in the primary reflector to permit theRF signal to pass from the secondary collector to the collector. Otherreflector configurations may also be used, such as that of FIG. 4 inwhich the reflector includes an asymmetric configuration. This case maybe used when the collector is positioned off axis from the reflector. Asshown in FIG. 4, the ribs 18 may extend across substantially an entirechord length from one side of the reflector to the other. As illustratedany configuration of one or more reflectors and collector may be usedaccording to embodiments described herein. The illustrated reflectorconfigurations are exemplary only and not intended to be limiting.

Exemplary reflectors include a support structure such as outer frame 14,ribs 18, and combinations thereof. The support structure supports thereflector 20. The reflector and/or support structure may be coupled toan object, such as the collector or other reflector, by struts 16.

In an exemplary embodiment, the support structure comprises an outerframe 14. The support structure may include any enclosed shapes such aselliptical, circular, polygon, clam shell, etc. The support structuremay comprise a curved structure or discrete linear sections angled withrespect to adjacent linear sections to approximate a curved surface.Exemplary embodiments include a torus outer frame.

In an exemplary embodiment, the support structure comprises ribs 18. Anynumber of ribs may traverse the enclosed space within the perimeter ofthe outer frame. Ribs 18 provide support for the reflective surface ofreflector 20. Ribs 18 may be used to define the shape of the reflectivesurface of reflector 20. Ribs may define a symmetric or asymmetricconfiguration. As shown in FIGS. 1-3, ribs may attach at one terminalend to the outer frame and extend toward each other to directly orindirectly attach to each other at an opposite terminal end. The ribsmay approach a central axis of the outer frame 14 to define a symmetricsupport structure. The ribs may be curved to define a desired reflectivesurface of the antenna. As seen in FIG. 3B, the ribs may extend out ofthe plane of the outer frame 14.

The ribs that define the reflector shape, such as an approximateparabolic shape, may be made with a cross section that increases itsarea moment of inertia for added stiffness such as an I-beam or aT-beam. The stiffness may also or alternatively be increased by theinclusion of cross-ribs coupled between adjacent ribs. FIG. 5illustrates an exemplary embodiment having cross-ribs for the offsetgeometry. However, such configuration may also be used for any known ordisclosed embodiment.

In an exemplary embodiment, struts 16 may be used to couple componentparts. For example, struts may extend between reflectors, betweenreflectors and collectors, or between any combination thereof or othercomponent. Struts may couple directly or indirectly to the supportstructure.

In an exemplary embodiment, the support structure, including outer frame14 and/or ribs 18, and/or struts 16 may comprise a shape memorycomposite material. The shape memory composite material permits theantenna to collapse under imposition of an outside force in anon-structured fashion. The collapsed configuration may therefore bedynamically determined based on the storage compartment or the outsideforce applied. For example, the shape memory composite may be flexibleor deformable along a length when a force is applied. The shape memorycomposite, however, returns to a remembered configuration, once theforce is removed. Therefore, exemplary embodiments may include a storedconfiguration in which the support structure is retained in the storedconfiguration having a reduced storage volume through application of anoutside force; and a deployed configuration in which the supportstructure is fully deployed having a larger storage volume when theoutside force is removed. In other words, the remembered or biasedconfiguration may be a deployed configuration in which the supportstructure is configured for use as an RF reflector. In an exemplaryembodiment, the shape memory composite may flex in any direction underapplication of an outside force. In an exemplary embodiment, the shapememory composite may flex at multiple locations along a length of themember or along an entire length of the member. In an exemplaryembodiment, the shape memory composite may return to a rememberedconfiguration, such as linear, circular, ovoid, curved, parabolic, orother predefined shape when the outside force is removed.

An exemplary shape memory composite material includes a base material ofone or more of carbon fabric or tows, Vectran, or Kevlar. The basematerial comprises strands. The strands may be generally aligned along alength of the structure, may include one or more aligned arrangements,may be wound or helically positioned, may be woven, or any combinationthereof. The shape memory composite material includes a matrix aroundand/or between the base material. The matrix may be silicone, urethane,or epoxy. Exemplary shape memory composite materials are described inco-owned patent application U.S. Patent Publication Number 2016/0288453,titled “Composite Material”.

In an exemplary embodiment, the reflector may include a flexiblemembrane having a highly reflective surface. The surface may be createdby coating, laminating, depositing, or otherwise attaching a material tothe membrane surface or from the membrane surface itself. In anexemplary embodiment, the membrane comprises mylar, kapton,polyurethane-coated nylon (PCN), tedlar, Teflon, other polyimide orplastic materials, and combinations thereof. The reflective coating mayinclude a layer of high conductivity metal, such as aluminum, silver,silver-inconel, and combinations thereof. The membrane may also be madeof a conductive material such as foils of aluminum or stainless steel aswell as carbon fabric or a conductive mesh. The membrane may alsoconsist of a laminate of a combination of some or all of the abovematerials. The surface may be coated with a layer of high conductivitymetal such as aluminum or silver or silver-inconel. The thickness of themetallization can be between 100 to 2,000 Angstroms.

In an exemplary embodiment, the reflector may include a monolithicsurface made of a shape memory composite material laminated with a layeror layers of metallized membrane such as mylar, kapton,polyurethane-coated nylon (PCN), tedlar, Teflon or other polyimide orplastic material. The shape memory composite may be coated with a layerof high conductivity metal such as aluminum or silver or silver-inconel,as described herein. The reflective coating may be directly on the shapememory composite material or on a membrane overlaying the shape memorycomposite material. In an exemplary embodiment, the monolithic surfaceof shape memory composite material may replace the struts and/or outerframe of the support structure. Essentially, the monolithic shape memorycomposite material becomes a self-supporting structure.

In an exemplary embodiment, the reflector element is a packageablemembrane coated with a layer of high conductivity metal. The membranemay be mylar, kapton, polyurethane-coated nylon (PCN), tedlar, teflon,or other polyimide or plastic material. The double curvature of themembrane is obtained via the joining of accurately-cut flat gores of themembrane joined by adhesive or material melting at the seams or with theuse of direct casting or thermo-forming. The support structures are thetoroidal ring, radial, ribs and struts. These are made of compositematerial consisting of one or a combination of carbon fabric or tows,Vectran, or Kevlar. The matrix of the composite may be silicone,urethane, or epoxy. The support structures are designed and fabricatedsuch that they are collapsible for folding-packaging and stowing. Theymay also be fabricated using shape memory composites. The composite ribsare fabricated to have the curvature necessary to achieve high antennagain and efficiency. As an example, for a parabolic surface reflector,all the ribs lie on the surface of the paraboloid. For packaging, thetoroidal ring, ribs, and struts are folded, similar to a foldingumbrella and the reflector membrane stowed between or over the ribs,struts, and toroidal ring. Deployment is effected by allowing thepackaged antenna to deploy to its final antenna configuration byreleasing the stored strain energy in its packaged (or stowed)configuration. By the very nature of the material of the supportstructures, their springiness is tailorable up and down the stiffnessscale at the time of fabrication.

However, the preferred embodiment of the CoSMeRA reflector designconsists of gores of a low-coefficient of thermal expansion polyimidemembrane coated with 1,500 angstroms of Silver-Inconel with the supportstructures made of a foldable shape memory carbon composite material.

In some cases, it may be preferable to have the support structures madeof hollow tubes, instead of foldable rods. Their deployment may beinitiated by the use of an onboard pump and an inflatant gas such asnitrogen, carbon dioxide, or other inert substances like helium orargon. Other gases may also be used, depending on the mission concept.

In an exemplary embodiment, the shape memory material may be used forall or only portions of the support structure. For example, thereflector outer frame may comprise shape memory material, while the ribscomprise conventional rigid segmented materials. Other combinations ofshape memory structures with conventional structures are alsocontemplated hereby. Therefore, any combination of shape memorycomposite materials, inflatable materials, rigidizable materials, orrigid materials across any combination of components are contemplatedhereby.

FIG. 6A illustrates an exemplary compactable deployable antennaconfiguration. As shown a support structure may be created by an outerframe 14 and a plurality of struts 16. The struts extend from the outerframe to the spacecraft or collector (referred to generally as the hub).The outer frame 14 and plurality of struts 16 define the supportstructure for the reflector 20. The support structure may comprise theshape memory composite as described above or other known material, suchas an inflatable, rigidizable, or static foldable structure. As shown,the support structure includes a toroidal outer frame and three struts.However, any number of struts, preferably two to six may be used. Thesupport structure defines an outer envelope or surface for which thereflective surface is fully contained. The support structure is thedeployable structure to define the shape of the deployed antenna.

The compactable deployable antenna includes a net-mesh 22 enclosed andsupported by the outer frame 14. FIG. 6B illustrates an elevated view ofthe net-mesh, with FIGS. 6C and 6D illustrating blown up views of notesof the net-mesh. The net-mesh may be any flexible material that providesa plurality of nodes 26 for attachment points as described herein. Whenthe outer frame is deployed, the net-mesh is expanded. A plurality ofnodes of the net-mesh are coupled to tension elements 24 that extendfrom the net-mesh to the hub. When the support structure is deployed,the tension elements are under tension and define the surface shape ofthe net-mesh. The net-mesh may define an out of plane, generally curvedstructure, from the outer frame, when in a deployed condition. Thetension elements may retain the net-mesh toward the hub.

The tension elements may provide supporting structures for reflectivemembranes. A reflector 20 may therefore be defined within the volumedefined by the net-mesh, outer frame, and struts. The reflector 20 maycomprise a plurality of panels coupled to the tension elements. Theposition of the panels may define the reflector shape. The reflectorsurface may approximate a curved surface by step-wise placement ofgenerally planar panels. The reflector 20 may comprise panels of mylar,kapton, polyurethane coated nylon (PCN) or tedlar coated with a layer of100 to 1500 Angstroms thick high-conductivity metal such as aluminum,silver, or silver-inconel. Other reflective surfaces as described hereinor known by a person of skill in the art may also be used.

In an exemplary embodiment, a highly compactable deployable antennaincludes a net-mesh with a perimeter toroidal ring support, three ormore struts, a plurality of strings (tension ties), a conductiveparabolic membrane surface, and combinations thereof (or combinationsfrom other embodiments described herein). Lightweight high stiffnesstension elements, strings, are attached to each of the nodes of thenet-mesh structure. The other end of each of the strings is attached atits opposite end to the hub. When the strings are tensioned bydeployment of the support structure, the net mesh deforms to the desiredcurved surface as illustrated to define, for example, an invertednet-mesh dome. The curved shape may be any surface of revolutionincluding but not limited to a paraboloid, sphere or a hyperboloid.Exemplary embodiments describing curved surfaces include theirapproximation by piece-wise planar or linear segments.

Low-stowed volume antennas with aperture diameters on the order of tensof meters, up to 100 m diameter can be fabricated using this design.

FIG. 6B illustrates the plan view of the net-mesh invert dome. Thereflector surface may consist of triangular conductive facets of mylar,kapton, polyurethane coated nylon (PCN) or tedlar coated with a layer of100 to 1500 Angstroms thick high-conductivity metal such as aluminum,silver, or silver-inconel. The triangular metallized facets look verysimilar to that shown in FIG. 6C. Each of the vertices of the metalizedtriangular facet may be attached to the tensioned string at theappropriate locations to form a desired surface of revolution; e.g. aparaboloid. Because the conductive membrane facets do not have to bestretched to a high film stress, the loads on the support structures(toroidal ring and struts) may be small. This translates to lower massfor the overall system.

The reflector may also be made of accurately-cut flat gores of themetallized membrane joined by adhesive or material melting at the seamsor with the use of direct casting or thermo-forming.

The support structure may include the toroidal ring and struts. Thesupport structure may be made of composite material consisting of one ora combination of carbon fabric or toes, Vectran, or Kevlar. The matrixof the composite may be silicone, urethane, or epoxy. The supportstructures are designed and fabricated such that they are collapsiblefor folding-packaging and stowing. They may also be fabricated usingshape memory composites. The net mesh of the reflector dome isfabricated to have the curvature necessary to achieve high antenna gainand efficiency. For packaging, the toroidal ring and struts are folded,similar and the reflector membrane stowed between or over the struts,and toroidal ring. Deployment may be effected by the use of either (a) aset of telescoping struts or (b) a set of struts and a toroidal ring,made from shape memory composite material, allowing the packaged antennato deploy to its final antenna configuration by releasing the storedstrain energy in its packaged (or stowed) configuration. By the verynature of the material of the support structures, their springiness maybe tailorable up and down the stiffness scale at the time offabrication.

In an exemplary embodiment, the support structures or portions of thesupport structures are made of hollow tubes. Deployment of the tubularsupport structures may be effected by the use of inflatant gas such asnitrogen, carbon dioxide, or other inert substance like helium or argon.Other gases may also be used.

To prevent tangling of the tension elements, each string may be packagedwithin two enclosures 28, one at the net-mesh end 30, and the otherattached at the opposite end 32, proximate the hub, as shown in FIGS.8A-8B. As the struts are deployed, the strings are pulled out of theirenclosure. The enclosure may be any circumferential enclosure, such as atube. The enclosure may be flexible and deformable, such that it doesnot have to retain a given shape, but simply separates one string fromanother.

It should be emphasized that many variations and modifications may bemade to the herein-described embodiments, the elements of which are tobe understood as being among other acceptable examples. All suchmodifications and variations are intended to be included herein withinthe scope of this disclosure and protected by the following claims.Moreover, any of the steps described herein can be performedsimultaneously or in an order different from the steps as orderedherein. Moreover, as should be apparent, the features and attributes ofthe specific embodiments disclosed herein may be combined in differentways to form additional embodiments, all of which fall within the scopeof the present disclosure.

Certain terminology may be used in the following description for thepurpose of reference only, and thus are not intended to be limiting. Forexample, terms such as “above” and “below” refer to directions in thedrawings to which reference is made. Terms such as “front,” “back,”“left,” “right,” “rear,” and “side” describe the orientation and/orlocation of portions of the components or elements within a consistentbut arbitrary frame of reference which is made clear by reference to thetext and the associated drawings describing the components or elementsunder discussion. Moreover, terms such as “first,” “second,” “third,”and so on may be used to describe separate components. Such terminologymay include the words specifically mentioned above, derivatives thereof,and words of similar import.

Conditional language used herein, such as, among others, “can,” “could,”“might,” “may,” “e.g.,” and the like, unless specifically statedotherwise, or otherwise understood within the context as used, isgenerally intended to convey that certain embodiments include certainfeatures, elements and/or states. However, such language also includesembodiments in which the feature, element or state is not present aswell. Thus, such conditional language is not generally intended to implythat features, elements and/or states are in any way required for one ormore embodiments or that one or more embodiments necessarily excludecomponents not described by another embodiment.

Moreover, the following terminology may have been used herein. Thesingular forms “a,” “an,” and “the” include plural referents unless thecontext clearly dictates otherwise. Thus, for example, reference to anitem includes reference to one or more items. The term “ones” refers toone, two, or more, and generally applies to the selection of some or allof a quantity. The term “plurality” refers to two or more of an item.The term “about” or “approximately” means that quantities, dimensions,sizes, formulations, parameters, shapes and other characteristics neednot be exact, but may be approximated and/or larger or smaller, asdesired, reflecting acceptable tolerances, conversion factors, roundingoff, measurement error and the like and other factors known to those ofskill in the art. The term “substantially” means that the recitedcharacteristic, parameter, or value need not be achieved exactly, butthat deviations or variations, including for example, tolerances,measurement error, measurement accuracy limitations and other factorsknown to those of skill in the art, may occur in amounts that do notpreclude the effect the characteristic was intended to provide. Forexample, the terms “approximately”, “about”, and “substantially” mayrefer to an amount that is within less than 10% of, within less than 5%of, within less than 1% of, within less than 0.1% of, and within lessthan 0.01% of the stated amount or characteristic. Numbers preceded by aterm such as “about” or “approximately” also include the recitednumbers. For example, “about 3.5 mm” includes “3.5 mm. For example, thedisclosure expressly contemplates being able a value or range proceededby a term such as “about” or “approximately” in this disclosure with orwithout such term.

Numerical data may be expressed or presented herein in a range format.It is to be understood that such a range format is used merely forconvenience and brevity and thus should be interpreted flexibly toinclude not only the numerical values explicitly recited as the limitsof the range, but also interpreted to include all of the individualnumerical values or sub-ranges encompassed within that range as if eachnumerical value and sub-range is explicitly recited. As an illustration,a numerical range of “about 1 to 5” should be interpreted to include notonly the explicitly recited values of about 1 to about 5, but shouldalso be interpreted to also include individual values and sub-rangeswithin the indicated range. Thus, included in this numerical range areindividual values such as 2, 3 and 4 and sub-ranges such as “about 1 toabout 3,” “about 2 to about 4” and “about 3 to about 5,” “1 to 3,” “2 to4,” “3 to 5,” etc. As another illustration, a numerical range of “about1 to about 5” would also include the embodiment of a range of “1 to 5.”This same principle applies to ranges reciting only one numerical value(e.g., “greater than about 1”) and should apply regardless of thebreadth of the range or the characteristics being described. A pluralityof items may be presented in a common list for convenience. However,these lists should be construed as though each member of the list isindividually identified as a separate and unique member. Thus, noindividual member of such list should be construed as a de factoequivalent of any other member of the same list solely based on theirpresentation in a common group without indications to the contrary.Furthermore, where the terms “and” and “or” are used in conjunction witha list of items, they are to be interpreted broadly, in that any one ormore of the listed items may be used alone or in combination with otherlisted items. The term “alternatively” refers to selection of one of twoor more alternatives, and is not intended to limit the selection to onlythose listed alternatives or to only one of the listed alternatives at atime, unless the context clearly indicates otherwise.

What is claimed is:
 1. A deployable antenna, comprising: a collector; asupport structure comprising a shape memory composite that is flexibleand deformable along a length when a force is applied and has aremembered configuration when the force is removed; and a reflectorconfigured to direct radio frequency waves received at the reflector tothe collector, wherein the deployable antenna comprises a stowedconfiguration in which the support structure is dynamically deformed anda deployed configuration in which the support structure is in theremembered configuration.
 2. The deployable antenna of claim 1, whereinthe support structure comprises a toroidal outer frame and at leastthree struts coupled to the outer frame, and the deployable antennacomprises a net-mesh attached to the toroidal outer frame, the net-meshdefining a plurality of nodes.
 3. The deployable antenna of claim 2,wherein a plurality of tension elements are attached to the plurality ofnodes, the tension elements in tension defining a deployed shape of thenet-mesh in the deployed configuration.
 4. The deployable antenna ofclaim 3, wherein the reflector is attached to the tension elements. 5.The deployable antenna of claim 4, wherein the reflector comprises aplurality of reflector membranes, each reflector membrane coupled toadjacent tension elements.
 6. The deployable antenna of claim 5, whereinthe support structure comprises a shape memory composite.
 7. Thedeployable antenna of claim 1, wherein the support structure comprises ashape memory composite.
 8. The deployable antenna of claim 7, whereinthe shape memory composite comprises a base material and a matrixmaterial.
 9. The deployable antenna of claim 8, wherein the basematerial comprises carbon fabric, carbon tows, Vectran, Kevlar, orcombinations thereof.
 10. The deployable antenna of claim 9, wherein thematrix material comprises silicone, urethane, epoxy, or combinationsthereof.
 11. The deployable antenna of claim 10, wherein the basematerial comprises strands and the matrix material fills a space betweenstrands.
 12. The deployable antenna of claim 11, wherein the strands aregenerally aligned along an entire length of the support structure. 13.The deployable antenna of claim 12, wherein the support structurecomprises an outer frame, a plurality of ribs coupled to the outerframe, and a plurality of struts coupled to the outer frame.
 14. Thedeployable antenna of claim 13, wherein the outer frame comprises atoroid and the struts extend out of plane of the outer frame andgenerally converge toward each other.
 15. The deployable antenna ofclaim 14, wherein the outer frame and struts support the reflector.